The present invention relates to creating a drainage plane and air space within a building structure to prevent the accumulation of moisture within the structure, and more particularly, the present invention relates to a spacer product which is utilized in a wall and/or roof construction and which provides a drainage path and air space adjacent both an inner sheathing member and an outer building material to retard deterioration of the structure.
An openwork member for use in providing a path of ventilation in a roof or wall of a building structure is disclosed in U.S. Pat. No. 5,099,627 which issued to Coulton et al. and which is assigned to the assignee of the present application. The openwork member is located between an inner sheathing member and an outer building material, such as wooden shingles. The openwork member provides vapor flow paths therethrough to prevent moisture from becoming entrapped adjacent the inner sheathing member and adjacent the outer building material. As disclosed in the ""627 patent, the preferred embodiment of an openwork member is made of a resilient matrix of matted self-supporting filaments providing multiple vapor flow paths therethrough.
A related form of vent is a roof ridge vent. Roof ridge vents have been provided by elongate, roll-form, sheet-like, thermoplastic webs as disclosed in U.S. Pat. Nos. 5,902,432 and 5,673,521 which issued to Coulton et al. and which are assigned to the assignee of the present application. These plastic sheet-like vents are thermoformed with hollow spacer elements projecting from one face thereof. Thus, one face of the vent is spaced from the roof ridge by the spacer elements and one face lies flush with overlying roof ridge cap shingles.
Another example of a roof ridge vent which utilizes spacer elements is U.S. Pat. No. 3,660,955 issued to Simon. The vent disclosed in the Simon patent provides a path for air circulation between overlapping shingles located on a roof ridge. A row of spacer elements are located between the overlapping shingles to provide and define ventilation paths. FIG. 12 of the Simon patent discloses an elongated strip of sheet material which has solid spacer elements secured to one face thereof and which can be provided in roll-form.
Although the above roof ridge vents made of sheet-like webs having spacer elements projecting from one face thereof have been considered as a cost effective replacement for the openwork member described in the above referenced ""627 patent, the sheet-like webs have a disadvantage in that they provide a drainage path and/or air space adjacent only one side of the vent, ie. the side of the vent with the spacer elements. Thus, if moisture accumulates on the side of the vent opposite the spacers, the moisture is entrapped by the vent and will cause premature deterioration of the building structure. Thus, use of such vents between an inner sheathing member and an outer building material is not recommended.
Entrapped moisture is particularly a problem on wall structures of buildings covered with a housewrap product. Typical housewraps utilized in building constructions are particularly engineered to permit the one-way passage of vapor therethrough so that moisture vapor can escape the building but cannot enter the building. Vapor which is permitted to pass through the housewrap must be provided with a drainage path through the remainder of the wall; otherwise, condensation will form and become entrapped within the wall. Thus, plastic sheet-like vents with spacer elements on one side thereof cannot provide drainage paths along both the inner sheathing member and the outer building component, and do not provide a transverse drainage path through the vent. For these reasons, their use in wall constructions is not recommended.
The plastic sheet-like vents are also not recommended for use in roof constructions. To this end, if the side of the vent without spacers confronts the inner roof deck, any moisture which leaks through the shingles and nailholes, or other cracks in the plastic vents, will be entrapped on the roof deck. Alternatively, if the side of the vent without spacers confronts the outer wooden shingles, moisture absorbed by the shingles will not dry adjacent to the vent and will therefore deteriorate.
Therefore, while plastic roll-form vents having spacer elements disclosed in the above referenced patents may function satisfactorily as roof ridge vents, there is a need for a roll-form spacer product made of a web of thermoplastic material which can be utilized in a wall and/or roof construction to provide drainage paths and air spaces between an inner sheathing member and an outer building material. The product should be capable of inexpensive manufacture and should provide drainage and/or ventilation paths along both the inner sheathing member and the outer building material. Preferably, the spacer product should also provide a transverse drainage path through the vent.
With the foregoing in mind, a primary object of the present invention is to provide an efficient and economical spacer product which is capable of being readily installed in a wall or roof structure between an inner sheathing member and an outer building material and which provides drainage passageways and air spaces adjacent both the inner sheathing member and the outer building material.
Another object of the present invention is to provide a roll-form plastic sheet-like spacer product which has hollow spacer elements and which is capable of providing a path for the escape of liquid/vapor adjacent an inner sheathing member and an outer building material.
A further object of the present invention is to provide a building structure which includes an inner sheathing member, a plastic spacer product, and an outer building material.
More specifically, the present invention provides a spacer product which provides a drainage pathway and air space within a building structure so as to retard deterioration of the building structure. The spacer product is a continuous, indeterminate-length, roll-form web of thermoplastic material having front and rear faces. The web is capable of being rolled lengthwise into a spiral roll during manufacture and unrolled lengthwise in a substantially straight direction during installation.
The web has a first set of hollow spacer elements integrally formed thereon and projecting outwardly from the front face. Each spacer element has an apex portion spaced from the front face. Thus, a first drainage path and air space extends along the front face of the web. The web also has a second set of hollow spacer elements which project outwardly from the rear face of the web in an opposite direction relative to the first set of spacer elements. Each spacer element in the second set has an apex portion spaced from the rear face for creating a second drainage path and air space which extends along the rear face. In some contemplated embodiments of the present invention, the web can be provided with a series of apertures formed therein for creating additional drainage/air flow paths extending transversely through the web. Alternatively, the web can be provided without apertures.
According to another aspect of the present invention, a building structure is provided having a drainage passageway and air space therein so as to retard deterioration of the building structure. The structure includes an inner sheathing member providing a wall or roof of a building structure, a web of thermoplastic material affixed to and overlying the inner sheathing member, and an outer building material affixed to the inner sheathing member and overlying the web.
The web has a front face, a rear face, and first and second sets of integrally formed hollow spacer elements. The sets of spacer elements project outwardly from both the front and rear face of the web in opposite directions. Each spacer element has an apex portion spaced from either the front or rear face for defining drainage pathways and air spaces adjacent and along the front and rear faces. The web can be provided with, or without, a series of apertures formed therein. If utilized, the apertures can create additional drainage/air flow paths transversely through the web.